The Therapeutic Role of rHDL Nanoparticles with Saquinavir in Fighting High Risk Neuroblastoma

Hypothesis: Our hypothesis is to determine how effective rHDL nanoparticles with saquinavir are in killing neuroblastoma cells. Specifically, we are looking to see how they effect specific cell lines that do express the SR-B1 receptor versus cell lines that do not express the SR-B1 receptor. We are also measuring the effect of rHDL with saquinavir versus free saquinavir in killing neuroblastoma cells. Materials and Methods: The rHDL-saquinavir nanoparticles were prepared by cholate dialysis method, and their biochemical composition was determined using standard assay kits for the different components of the nanoparticle. The average size of the particles was measured using DeLsa Nano particle size analyzer. The cytotoxic effect of the rHDL-saquinavir combination versus free saquinavir was measured against a HRNB cell line, SMS-KCNR, using a CCK-8 kit. Results: The most pertinent result came from the cytotoxicity assay, which showed that free saquinavir was more effective than rHDL with saquinavir in killing neuroblastoma cells from the SMS-KCNR cell line, which has low expression of SR-B1. This is contrary to the previous experiment (from last years data on this same project) which showed that rHDL wth saquinavir was more effective than free saquinavir in killing neuroblastoma cells from the IMR-5 and SJNKP cell lines, which have high expression of SR-B1. Conclusions: From this project, we were able to conclude several things. First was that saquinavir was successfully incorporated into rHDL capsules to form a viable nanoparticle. The particle was also small enough to be incorporated into the cells. The biggest and main conclusion was that the SR-B1 receptor plays a key role in regulating uptake of the rHDL nanoparticles. Cells lines that had high expression of SR-B1 showed more uptake of the nanoparticles, and therefore more cell death. Cell lines that had low levels of expression of SR-B1 showed less uptake of the nanoparticles, and therefore less cell death. Free saquinavir showed more effective killing of cancer cells than encapsulated saquinavir when SR-B1 levels were low. Ergo, cancers that express high levels of SR-B1 can be targeted with encapsulated chemotherapeutic agents such as rHDL. Overall, rHDL nanoparticles are a novel therapeutic treatment strategy that can potentially be used in patients with high risk neuroblastoma as well as other forms of cancer.